Home automation systems, which have become increasing popular, may be used by homeowners to integrate and control multiple electrical and/or electronic devices in their house. For example, a homeowner may connect appliances, lights, blinds, thermostats, cable or satellite boxes, security systems, telecommunication systems, or the like to each other via a wireless network. The homeowner may control these devices using a controller or user interface provided via a phone, a tablet, a computer, and the like directly connected to the network or remotely connected via the Internet. These devices may communicate with each other and the controller to, for example, improve their efficiency, their convenience, and/or their usability.
A wall-mounted load control device may be adapted to be mounted in a standard electrical wallbox. For example, a wall-mounted dimmer switch may be coupled in series electrical connection between an alternating-current (AC) power source and an electrical load (e.g., a lighting load) for controlling the power delivered from the AC power source to the lighting load and thus the intensity of the lighting load. Many prior art wall-mounted load control devices are capable of transmitting and/or receiving wireless signals (e.g., radio-frequency (RF) signals) with other control devices in a load control system. For example, a wireless load control device may be configured to receive digital messages via the RF signals for controlling the electrical load and to transmit digital messages including feedback information regarding the status of the load control device and/or the electrical load. Such wall-mounted wireless load control devices have included antennas for transmitting and/or receiving the RF signals. Examples of antennas for prior-art wall-mounted load control devices are described in commonly-assigned U.S. Pat. No. 5,982,103, issued Nov. 9, 1999, and U.S. Pat. No. 7,362,285, issued Apr. 22, 2008, both entitled COMPACT RADIO FREQUENCY TRANSMITTING AND RECEIVING ANTENNA AND CONTROL DEVICE EMPLOYING SAME, the entire disclosures of which are hereby incorporated by reference.
The components and/or building structure surrounding the location at which a wall-mounted wireless load control device is installed may affect the communication range (e.g., the transmission and/or reception range) of the control device. For example, the control device may be mounted in an electrical wallbox, and the electrical wallbox may be made of a conductive material (e.g., a metal) or a non-conductive material (e.g., a plastic). In addition, a faceplate may be mounted to the load control device, and a part or the entirety of the faceplate may be made of a conductive material (e.g., a metal) or a non-conductive material (e.g., a plastic). When the wall-mounted wireless load control device is installed in a metal wallbox or with a faceplate assembly made of metal, electric fields that are produced when the antenna is transmitting an RF signal may cause current to flow through the metal wallbox and/or through the metal faceplate assembly, which in turn may affect the transmission and/or reception range of the antenna.
The possible differences in the materials surrounding the installation location of the wall-mounted wireless load control device may cause the communication range of the load control device to vary from one installation to another. However, it is desirable to have a consistent communication range and performance of the wall-mounted wireless load control device from one installation location to the next.
In addition, if the faceplate assembly mounted to the wireless load control device includes a large amount of metallization on the front (or outer) surface of the faceplate, the communication range of the wireless load control device may be diminished to a point that the wireless load control device may not able to communicate with the other RF-enabled components of the load control system. Since conductive faceplates typically provide an attractive aesthetic appearance, it is desirable to install conductive faceplates on wall-mounted wireless load control devices. Therefore, there is a need for a wall-mounted wireless load control device that is able to operate properly while installed with a conductive faceplate.